By Nicholas Bakalar

Published: May 22, 2007

The bone loss caused by gum disease is associated with an increased risk for tongue cancer, and the more the bone loss, the greater the risk, researchers report.

Scientists evaluated bone loss around the teeth in 51 men with newly diagnosed tongue cancer and in 54 men without the diagnosis. X-rays were taken of the men's jaws, and a radiologist who did not know the cancer status of the men measured the amount of bone loss. The study took place from 1999 to 2005.

After adjusting for smoking status, sex, race and ethnicity, number of cavities, crowns, fillings and missing teeth, the researchers calculated that for every one millimeter of bone loss, the risk of tongue cancer increases more than fivefold.

Chronic infection, the authors write in the May issue of The Archives of Otolaryngology: Head & Neck Surgery, can play a role in cancer, either directly by the effect of the toxic products of micro-organisms, or indirectly by inflammation that stimulates the formation of tumors.

''I was surprised by the magnitude of the effect,'' said Frank A. Scannapieco, the senior author and a professor of oral biology at the School of Dental Medicine at the State University of New York at Buffalo. But, he added, ''There have to be more population-based studies to support these conclusions.''

Although chronic gum disease was the only oral variable significantly associated with oral cancer, the authors acknowledged that the number of people in the study was small and that the diagnoses of periodontal disease were made from X-rays rather than direct measurement.